1. Field of the Invention
The present invention relates to a personal authentication apparatus that registers biometric information unique to each individual person, and obtains the person's biometric information anew when performing authentication, and checks it against the registered biometric information to authenticate the person.
2. Description of the Related Art
Facilities and equipment that require personal authentication for the opening and closing entrance doors of rooms or buildings or operating information processing devices in order to improve security or protect privacy have proliferated in recent years. For such authentication, code numbers have been widely used traditionally. In recent years, more secure personal authentication methods are becoming widespread in which sensors are provided to detect some biometric information unique to every individual, such as fingerprints or palm or pupil vein patterns, for performing personal authentication (see Japanese Patent Laid-Open No. 2003-85539 and No. 2004-112172).
A problem with a code number is that, if it is known to another person, the person can readily impersonate the holder of the code number. In contrast, personal authentication that relies on biometric information, which varies from person to person, can significantly reduce threat of impersonation.
In a system in which biometric information is used for personal authentication, IDs are associated with the biometric information and used in addition to the biometric information for greater security or for convenience of management (Japanese Patent Laid-Open No. 11-338947 and No. 2001-290959).
When biometric information is used in combination with an ID, a problem arises as to whether different IDs should be assigned to different individuals. For example, for controlling access of workers to a factory or an office building, it is desirable that IDs be unique to individual workers, whereas for controlling access to a complex housing such as an a condominium, IDs unique to individual dwelling units, rather than to individuals, are preferable because the dwellers may include young children and elderly people. In the latter case, the same ID may be assigned to a number of people.